Drying of timber or other materials



'June 25, 193.5. c. GooDALI. 2,006,018

DRYINGOF TIMBER 0R OTHER MATERIALS l Y Filed March l5, 1954 2Sheets-Sheet 1 J-fi s Il 0 (e gli H /0 s I vim-rm l '1 -J- J: p/ \d l p/V /j/I \//l/// h v1 k b e le l \n/ L il ll Il i L iL iL iL i r- L IL illl ll m --a ll il iL il i T EilTilL-i-ili S l iL il iL i l I IL IL Il lL IL IL ll l CLJ l IL lL il i c I II il lI il n ll il il iL l I IL iL illb I iL iL iL i l I Il il Il i nl 1I iI il l L II iL II I I il il ll i lL IL IL 1L il l il lI il l \`L i L iL II L, l il il IIJQL Flgl Cmo/@MJune 25, 1935. c. GooDALL l ,DRYING 0F TIMBER 0R OTHER MATERIALS FiledMarh l5, l954 2 Sheets-Sheet .2

T1110 wf. il. 1111 i 1| l, -i illllfnfufv LHLII Film Patented June 25,1935 UNITED STATES DRYING OF TIMBER OR OTHER MATERIALS Charles Goodall,Tutbury, Burton-on-Trent, England Application March 15, 1934, Serial No.715,709 In Great Britain December 30, 1933 2 Claims.

This invention relates to apparatus for use vin the drying of timber andother materials, the apparatus being of the kind comprising a chamber inwhich the materials can be stacked with "5 air spaces between them, andmeans for producing a flow of air or other gases through the saidspaces.

The object of the present invention is to provide improved apparatus inwhich the flow of air can be more effectively regulated so as to produceuniform drying of all parts of the materials stacked in the chamber.

By the term air I mean not only atmospheric air but any gas or mixtureof gases which can be advantageously used for the purpose of drylng thematerials undergoing treatment in the chamber.

In the two accompanying sheets of explanatory drawings:-

Figure 1 is a cross section and Figure 2 a plan of a portion of a timberdrying apparatus constructed in accordance with this invention.

In carrying the invention into effect as shown, I employ a chamber a ofrectangular cross section. The timber b or other material to be dried isstacked on the floor of the chamber, horizontal spaces being arrangedbetween the successive layers of the stack. Spaces c are also providedat the two sides of the stack, and another space d is provided at thetop of the stack.

At the upper end of each of the side spaces c are arranged inlets e fora stream of air supplied by a fan or blower f driven by an electricmotor g. Outlets h which may be controlled by dampers w are alsoarranged at the top of the chamber. One or more of the outlets may beconnected to the inlet of the fan, so that the fan may draw air eitherfrom the chamber or from the outer atmosphere. The connection betweenthe fan and the outer atmosphere is controlled by a damper z'. Furtheran air heater y' may be arranged at any convenient position, as forexample, at the outlet of the fan.

On looking at the plan in Figure 2, it will be seen that air is suppliedto the inlet apertures e by a culvert k connected to the delivery sideof the fan. To enable air to be delivered to either of the spaces c theculvert 7c is provided with a pivoted flap valve l whereby the airstream from the blower can be delivered to either the left hand or theright hand side space c of the drying chamber.

Within each of the side spaces c is mounted a deector m which isdisposed in the path of the air stream, leaving a space between it andthe adjacent side of the stack. These two deectors are interconnected bycords, chains, or other exible means n passing over pulleys o carried onshafts p, one of which is driven by an electric motor q throughreduction gearing 1', so that a rising or falling movement of eitherdeflector is accompanied by the opposite movement of the other deector.Each deflector receives a slow and continuous up and down movement.

Assuming one of the deflectors m to be in its lower position as shown atthe left hand side of Figure 1, and the other in its upper position asshown at the right hand side, air owing down the left hand space c isdeflected laterally and caused to flow horizontally throughl the spacesin the stack adjacent to the deflector. After passing through the stackthe air rises in the right hand space and is returned to the fan or isallowed to escape to the atmosphere. With the slow upward movement ofthe left hand deecto'r m the position at which the air is deflected intothe stack is progressively varied, so that during the movement of thedeflector from its lower to its upper position the air stream is causedto pass through all of the horizontal spaces of the stack. When thedeiiector reaches the upper position its motion is reversed. Thereversal of motion of the deflectors is also accompanied by reversal ofthe air stream, so that while the left hand deflector is descending airis directed down the right hand space and is deilected horizontally bythe right hand deilector, the air being now caused to flow horizontallythrough the stack in the reverse direction to that rst described. Afterowing down the right hand space until the right hand deector reaches thetop of its movement, the air stream is again reversed so that it flowsdown the left hand space, and the cycle above described is repeated.

By proceeding as above described, the horizontal part of the air streamis at any given instant localized in a part of the stack, and theposition at which the stream passes through the stack gradually changes.Previously it has been the practice in timber drying processes to causethe air to pass through all parts of the stack at the same time, andthis has resulted in certain disadvantages which are avoided by mypresent invention. It is well known that in the drying of timber thereis always present a risk of excessively rapid drying (or case hardening)of the surfaces exposed to the air stream. One of the consequences ofthis condition is that the moisture contained in the inner parts of thetimber is not removed by the continued action of the air stream, andanother consequence is that the surface portions of the timber areliable to develop cracks. When timber is treated by my present processthe action of the air stream on any given part of the stack isintermittent because the position at Which the stream is being directedinto the stack is continuously being changed. While the air is iiowingmoisture is being removed, but the time for which the flow is maintainedat a given part of the stack is relatively small, and during the periodsin which no air is iiowing through that part moisture can diffuse out ofthe interior of the` timber to the dried or drier outer surfaces priorto removal when the air stream is again directed over that part. In thisway I am able to ensure thorough and uniform drying without cracking ordistortion', and also I am able to reduce the normal total time requiredfor drying.

Periodic reversal of movement of the air current is convenientlyeffected by arranging on one of the chains or the like n a pair ofstrikers s either of which can engage a lever t on the valve Z and causeit to swing to slightly beyond its central position, thevmovement of thevalve being completed by pressure of the air acting on the valve. At thesame time the same striker s engages a lever u on a 4reversing switch Ucontrolling the motor g, and by operating the switch causes the motionof the motor to be reversed. At the end of the next phase in themovement of the deflectors the otherstriker s will engage the levers andeffect reversal of the air valve and switch.

Instead of admitting the air at the top of the side spaces it may beintroduced at the bottom. Also the air may be withdrawn from the bottomof the drying chamber if desired.

The invention is not limited to the example above described assubordinate details may be varied to suit different requirements.

Having thus described my invention what I claim as new and desire tosecure by Letters Patent is:--

1. In apparatus for use in the drying of timber or other materials, thecombination of a chamber in which the timber or other material can bestacked leaving spaces within and around the stack, a deflectorvertically movable in each side space and adapted to direct the airhorizontally through the stack, exible means interconnecting thedeflectors so that upward movement of one is accompanied by downwardmovement of the other, reversible actuating means for the deflectors, afan, means for conveying air from the fan into each side spacealternately, a reversing valve situated between the fan and chamberinlets, and a striker associated with the deector actuating mechanismfor reversing the said valve, substantially as described.

2. In apparatus for use in the drying of timber or other materials, thecombination of a chamber in which the timber or other materials can bestacked leaving spaces within and around the stack, means for deliveringair into the two side spaces in the chamber, deectors situated in thesaid side spaces, a plurality of flexible elements interconnecting thedeiiectors, guide pulleys supporting the said elements, shafts carryingthe said pulleys, a reversible electric motor connected to one of theshafts, a reversing switch, and a striker on one of the said elementsfor actuating the switch, substantially as described.

CHARLES GOODALL.

